Manufacturing a lead-acid battery that includes a composite that includes lead oxide and a nanomaterial

ABSTRACT

The disclosure relates to the manufacturing of a lead-acid battery that includes a composite that includes lead oxide and a nanomaterial. A method of preparing the composite is disclosed. In one embodiment, an in-situ sol-gel reaction of a solution occurs in the presence of lead oxide to produce a composite that includes the lead oxide and a nanomaterial (e.g., a nano-oxide). The solution may include a precursor that includes metal alkoxide or silicate. The composite may include the lead oxide and the nanomaterial dispersed or distributed among particles of the lead oxide. A lead-acid battery may be manufactured using the composite. Various properties of a lead-acid battery may be improved by using the composite as part of the active material including a longer life expectancy, increased specific energy and increased power-to-weight ratio.

The present application is a continuation of and claims the benefit ofU.S. application Ser. No. 14/635,928, filed on Mar. 2, 2015, which isincorporated by reference herein in its entirety.

BACKGROUND

An electric battery is an energy storage device that converts chemicalenergy into electrical energy. A typical battery design includes apositive electrode and a negative electrode. A typical battery designalso includes an electrolyte that facilitates ion exchanges between thepositive and negative electrodes. Current flows out of the battery toperform work as a result.

Batteries may be divided into disposable batteries and rechargeablebatteries. An example of a rechargeable battery may include lead-acidbatteries. Lead-acid batteries may be used in a variety of applications.For example, lead-acid batteries may be used as starting and poweringbatteries or as a source of back-up power to ensure continuous energysupply to uninterruptible services such medical services or datamaintenance services. Lead-acid batteries come in a variety of types,sizes and capacities. Valve regulated lead-acid batteries or sealedlead-acid batteries are among the many varieties of lead-acid battery.

Generally speaking, lead-acid batteries are considered to be acost-effective, versatile, and reliable. Other advantages of lead-acidbatteries may include high charge retention, low-self discharge and lowmaintenance requirements. There is a continuous need to improve thepower density, efficiency and life expectancy of lead-acid batteries.

SUMMARY

In an embodiment, a method includes: preparing a first mixturecomprising a polar organic solvent, water, a polymer, and a metalalkoxide; combining lead oxide with the first mixture to form a secondmixture; and heating the second mixture to a temperature sufficient toinitiate an in-situ sol-gel reaction of the second mixture, producing acomposite that includes the lead oxide and a nanomaterial formed fromthe metal alkoxide. The method may further include adding a catalyst tothe first mixture, wherein the catalyst comprises an acidic catalyst oran alkaline catalyst. The method may further include removing, from thecomposite, at least a portion of the water.

The produced nanomaterial may have a grain size that is between about 1nanometer and about 100 nanometers. In some embodiments, thenanomaterial is an oxide of the metal alkoxide.

In some embodiments, the polymer is a hydrophilic polymer.

The lead oxide may be in a powder form having a grain size of betweenabout 1 micrometer and about 50 micrometers. The lead oxide comprises atleast one of: lead monoxide, lead dioxide, or triplumbic tetroxide.

In some embodiments, the metal alkoxide is a silicon alkoxide or atitanium alkoxide.

In some embodiments, the polar organic solvent is an alcohol.

In some embodiments, the first mixture includes: 1 part of the metalalkoxide, 20 to 200 parts of the polar organic solvent, 0.01 to 0.1parts of water and 0.0001 to 0.02 parts of the polymer.

In another embodiment, a method includes: preparing a first mixturecomprising water, a polymer, and a metal silicate; combining lead oxidewith the first mixture to form a second mixture; and heating the secondmixture to a temperature sufficient to initiate an in-situ sol-gelreaction of the second mixture, producing a composite that includes thelead oxide and a nanomaterial formed from the metal silicate. The methodmay further include adding a catalyst to the first mixture, wherein thecatalyst comprises an acidic catalyst or an alkaline catalyst. Themethod may further include removing, from the composite, at least aportion of the water.

The produced nanomaterial may have a grain size that is between about 1nanometer and about 100 nanometers. In some embodiments, thenanomaterial is an oxide of the metal alkoxide.

In some embodiments, the polymer is a hydrophilic polymer.

The lead oxide may be in a powder form having a grain size of betweenabout 1 micrometer and about 50 micrometers. The lead oxide comprises atleast one of: lead monoxide, lead dioxide, or triplumbic tetroxide.

In some embodiments, the metal silicate is silicon silicate, lithiumsilicate, or potassium silicate.

In some embodiments, the first mixture includes: 1 part of the silicate,5 to 20 parts of water and 0.0001 to 0.02 parts of the polymer.

In an embodiment, the first mixture may be formed by: using an ionexchange resin to process an aqueous solution of the silicate, whereinthe silicate comprises at least one of: sodium silicate, potassiumsilicate, or lithium silicate; and adding polymer to the processedsilicate solution.

In an embodiment, a lead-acid battery includes a composite produced bythe methods set forth above. The lead-acid may include a positiveelectrode and/or a negative electrode that includes the composite.

In an embodiment, a composite includes: metal oxide particles having agrain size that is between about 1 nanometer and about 100 nanometersand lead oxide particles having a grain size of between about 1nanometer and about 100 nanometers.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a representation of a lead-acid battery.

FIG. 2 illustrates a method of making a component of a lead-acid batteryaccording to an embodiment of the disclosure herein.

FIG. 3 illustrates an in-situ sol-gel reaction according to anembodiment of the disclosure herein.

FIG. 4 illustrates a method of making a lead-acid battery according toan embodiment of the disclosure herein.

FIG. 5 illustrates an alternative method of making a component of alead-acid battery according to an embodiment of the disclosure herein.

DETAILED DESCRIPTION

This specification includes references to “one embodiment” or “anembodiment.” The appearances of the phrases “in one embodiment” or “inan embodiment” do not necessarily refer to the same embodiment.Particular features, structures, or characteristics may be combined inany suitable manner consistent with this disclosure.

Various devices, units, circuits, or other components may be describedor claimed as “configured to,” “usable to,” or “operable to” perform atask or tasks. In such contexts, “configured to,” “usable to,” and“operable to” are each used to connote structure by indicating that thedevices/units/circuits/components include structure that performs thetask or tasks during operation. As such, thedevice/unit/circuit/component can be said to be configured to, usableto, or usable to perform the task even when the specifieddevice/unit/circuit/component is not currently operational (e.g., is noton or in operation). The devices/units/circuits/components used with the“configured to,” “usable to,” or “operable to” language may includeelectronic hardware—for example, circuits, memory storing programinstructions executable to implement the operation, etc.—mechanicaldevices, or other types of structure. Reciting that adevice/unit/circuit/component is “configured to,” “usable to,” or“operable to” perform one or more tasks is expressly intended not toinvoke 35 U.S.C. § 112(f), for that device/unit/circuit/component.

A lead-acid battery is an electrochemical energy storage device thatuses a reversible chemical reaction to store energy. A typical lead-acidbattery may contain a combination of positive and negative plates and anelectrolyte such as sulfuric acid to convert electrical energy intochemical energy or from chemical energy into electrical energy.

The negative plate may include a metal such as lead. The positive platemay include lead oxide. During discharge cycles, the lead metal (Pb) onthe negative plate reacts with the electrolyte (e.g., sulfuric acid orH₂SO₄) to produce lead sulfate (PbSO₄), whereas the lead oxide (PbO₂) onthe positive plate also reacts with the sulfuric acid (H₂SO₄) to producelead sulfate (PbSO₄). As a result of the reactions, sulfuric acidbecomes mostly water.

During charging cycles, the lead-acid battery may receive electrons froman external electrical circuit, and PbSO₄ on the negative and positiveplates are converted to Pb and PbO₂, respectively.

In a typical lead-acid battery design, the positive and negative platesmay each be supported by a grid. The grid may include a number ofperforations that may be filled with a paste (sometimes called a batterypaste). The composition of the paste may depend on the raw materials andthe chemical or physical reactions that the raw materials undergo. In alead-acid battery, the paste used for a negative plate may be the sameor different from the paste used for a positive plate.

FIG. 1 illustrates a representation of lead-acid battery 100. Lead-acidbattery 100 may include negative plate 104. Negative plate 104 mayinclude a paste that includes Pb. The paste may be applied over a grid(not in view) to form negative plate 104. During a discharging cycle,negative plate 104 may donate electrons (illustrated as “e”) viaelectrical connection 112.

Lead-acid battery 100 may also include positive plate 106. A surface ofpositive plate 106 may include a paste having an active material such aslead oxide. The paste may be applied over a grid (not in view) to formpositive plate 106. Positive plate 106 may receive electrons during acharging cycle via electrical connection 112.

Lead-acid battery 100 may include electrolyte 102. In this particularillustration, electrolyte 102 includes H₂SO₄ and water (H₂O). In otherembodiments, however, electrolyte 102 may include other types ofelectrolyte not limited to H₂SO₄. In addition to being in aqueous formin this illustration, electrolyte 102 may include other mobile orimmobile forms of electrolyte.

Both negative plate 104 and positive plate 106 may be immersed inelectrolyte 102. Electrolyte 102 may serve as a conduit for electrons toflow between positive and negative plates 104 and 106. The chemicalreactions involved in lead-acid battery 100 may include:Pb+SO₄ ²⁻=PbSO₄+2e (negative plate 104)PbO₂+SO₄ ²⁻+4H++2e=PbSO₄+2H₂O (positive plate 106)Pb+PbO₂+2H₂SO₄=2PbSO₄+2H₂O (total reaction)

The chemical reactions shown may result in a surplus of electrons atnegative plate 104 while a deficit of electrons may exist at positiveplate 106. More specifically, when discharging, the electrons atnegative plate 104 and the electrons from electrolyte solution 102 moveto positive plate 106. When charging, the reverse occurs.

Lead-acid battery 100 may include separator 110. Separator 110 may beconfigured to electrically isolate negative plate 104 from positiveplate 106. In some embodiments, however, separator 110 is optional andnot required.

Turning now to FIG. 2 in which method 200 for making a composite for usein a lead-acid battery is illustrated. Specifically, method 200 isdirected to making a portion of a lead-acid battery such as lead-acidbattery 100. Method 200 starts at block 210.

At block 210, a first mixture is formed. The first mixture may be acolloidal solution. In one embodiment, a first mixture may be formedthat includes a polar organic solvent, water, a polymer and a metalalkoxide. In an alternate embodiment, the first mixture includes water,a polymer and a silicate. In one embodiment, the first mixture mayinclude: 1 part of metal alkoxide, 20 to 200 parts of solvent, 0.01 to0.1 parts of water and 0.0001 to 0.02 parts of polymer. In anotherembodiment, however, the first mixture may include: 1 part of silicate,5 to 20 parts of water and 0.0001 to 0.02 parts of polymer.

A metal alkoxide has the general formula M(OR)_(x), where M is a metal,R is an alkyl group having 1 to 6 carbon atoms and x is 3-5 and isselected to match the valence of the metal (M). M may be any metalsuitable for an alkoxide with an alcohol. Exemplary metals, M, include,but are not limited to Si, Ti, and K. Preferred metal alkoxides include,but are not limited to: tetramethyl orthosilicate (e.g., Si(OCH₃)₄),tetraethyl orthosilicate (e.g., Si(OC₂H₅)₄), tetrabutyl titanate (e.g.,Ti(OC₄H₉)₄), titanium ethoxide (e.g., Ti₄(OC₂H₅)₁₆), titaniumisopropoxide (e.g., Ti(OC₃H₇)₄), titanium tert-butoxide (e.g.,Ti(OC₄H₉)₄). A single metal alkoxide may be used in the first mixture orany combination of metal alkoxides may be used.

The silicate may include at least one of: sodium silicate (e.g.,Na₂SiO₃, Na₄SiO₄, or a combination of Na₂SiO₃ and Na₄SiO₄), potassiumsilicate (e.g., K₂SiO₃, K4SiO₄, or a combination of K₂SiO₃ and K₄SiO₄),or lithium silicate (e.g., Li₂SiO₃, Li₄SiO₄, or a combination of Li₂SiO₃and Li4SiO₄). In certain embodiments, the silicate may be in aqueousform, that is, the aqueous form of the silicate may include at least oneof: sodium silicate in aqueous form (may also be referred to as “sodiumwater glass”), potassium silicate in aqueous form (may also be referredto as “potassium water glass”), or lithium silicate in aqueous form (mayalso be referred to as “lithium water glass”). Other forms of silicatemay be specifically contemplated and included here.

As used herein the term “organic solvent” refers to an organic compoundthat is a liquid at or about room temperature (e.g., at about 25Celsius) and has a boiling point of less than about 140 Celsius. A polarorganic solvent, as used herein, is an organic solvent having adielectric constant greater than about 5. The polar organic solvent, insome embodiments, may be an alcohol. Exemplary alcohols include, but arenot limited to, methanol (e.g, CH₃OH), ethanol (e.g., CH₃CH₂OH),isopropyl alcohol (e.g., CH₃CH(OH)CH₃), n-butanol (e.g.,CH₃CH₂CH₂CH₂OH), isobutanol (e.g., (CH₃)₂CHCH₂OH), tert-butyl alcohol(e.g., (CH₃)₃COH). Other exemplary polar organic solvents include, butare not limited to, acetone (e.g., CH₃C(O)CH₃), acetylacetone (e.g.,CH₃C(O)CH₂C(O)CH₃), butanone (e.g., CH₃C(O)CH₂CH₃), ethanolamine (e.g.,NH₂CH₂CH₂OH) One or more polar organic solvents may be used in the firstmixture.

The polymer may include a naturally occurring polymer or a syntheticpolymer. In some embodiments, the polymer may be a hydrophilic polymer.In some embodiments, the polymer may be a water soluble polymer.Exemplary polymers include, but are not limited to: polyethylene glycol,polyvinyl alcohol, polyacrylamide, phenol formaldehyde resin, a collagenbased polymer, polyethyleneimine, polyacrylic acid, polymethacrylicacid, or cellulose. In some embodiments, the polymer may facilitatestabilizing the solution.

In a non-limiting embodiment, a catalyst may be added to the firstmixture. In one non-limiting embodiment, the catalyst may include anacidic catalyst. The acidic catalyst may include at least one of: nitricacid, sulfuric acid, hydrochloric acid, phosphoric acid, propionic acid,acetic acid, formic acid, tartaric acid, citric acid, salicylic acid,oxalic acid, or any combination thereof. In an alternative embodiment,however, an alkaline catalyst may be added to the first mixture. Thealkaline catalyst may include at least one of: ammonia, ethanol amine,diethanolamine, triethanolamine, sodium hydroxide, potassium hydroxide,lithium hydroxide, magnesium hydroxide, or any combination thereof.Other catalysts are specifically contemplated and included here.

The operation proceeds to block 220. At block 220, the produced firstmixture is combined with lead oxide to produce a second mixture. In onenon-limiting embodiment, the lead oxide being combined with the solutionis in powder form. For example, lead oxide having a grain size that isbetween 1 micrometer and 50 micrometers may be considered to be inpowder form. However, the lead oxide is not limited to a particulargrain size or a particular grain size range. The lead oxide may includeat least one of: lead monoxide (e.g., PbO), lead dioxide (e.g., PbO₂),triplumbic tetroxide (e.g., Pb₃O₄), or any combination thereof.

At block 230, the second mixture is heated to a temperature sufficientto initiate an in-situ sol-gel reaction of the second mixture. Thein-situ sol-gel reaction produces a composite that includes the leadoxide and a nanomaterial formed from the metal alkoxide. In someembodiments, the in-situ sol-gel reaction may result in a gel such as ahydrophilic gel. The gel may undergo further processing (e.g., waterand/or solvent removal) to produce the composite.

For example, a first mixture may be prepared hat includes a metal oxidesuch as tetraethyl orthosilicate (e.g., Si(OC₂H₅)₄) (which may also bereferred to as TEOS, ethyl orthosilicate, or other names or trade namesused in the industry). When an acidic or alkaline catalyst is applied tothe tetraethyl orthosilicate, water in the first mixture reacts with theTEOS to produce silicic acid Silicic acid may be a compound thatincludes a silicon element and one or more hydroxyl groups. For example,Si(OH)₄ is a silicic acid that includes one silicon element and fourhydroxyl group. Based on an in-situ sol-gel reaction, the silicic acidmay produce a polymeric silica gel, a form of silicon dioxide (e.g.,SiO₂). For example, the silicic acid may lose water to form thepolymeric silica gel during a condensation reaction that may be includedin the in-situ sol-gel reaction.

A nanomaterial as used herein, may include a material in which a singleunit (e.g., a particle) is sized (in at least one dimension) between 1and 100 nanometers. In one non-limiting embodiment, the nanomaterialin-situ formed in the presence of lead oxide may have a grain size thatis between 1 nanometer and 100 nanometers.

The nanomaterial may include an oxide. The oxide may include a compoundthat includes at least one oxygen atom and at least one metal element.For example, the nanomaterial may include at least one of: silicondioxide (e.g., SiO₂), titanium dioxide (e.g., TiO₂) or a combinationthereof. Other oxides are specifically contemplated and included here.In a non-limiting embodiment, the composite may include nano-sizedsilicon dioxide (e.g., SiO₂) having a grain size between 1 nanometer and100 nanometers. In this or an alternative embodiment, the composite mayinclude nano-sized titanium dioxide (e.g., TiO₂) having a grain sizebetween 1 nanometer and 100 nanometers.

The in-situ sol-gel reaction may occur under either acid or basiccondition. In certain embodiments, the pH value of the in-situ sol-gelreaction may be within a range between 2 and 11. In an alternativeembodiment, however, the pH value of the in-situ sol-gel reaction may beoutside of that range. The in-situ sol-gel reaction may occur over atemperature range between 40 Celsius and 80 Celsius.

In one particular embodiment, the in-situ sol-gel reaction may form thecomposite by causing the nanomaterial to be distributed among lead oxideparticles. The in-situ sol-gel reaction may prevent the nanomaterialfrom aggregating among the lead oxide particles by facilitating thenanomaterial to form a porous network among the lead oxide particles.The nanomaterial may be dispersed or distributed among the lead oxideparticles. Operation ends at block 230.

The composite may subsequently undergo a process in which water and/orsolvent may be removed. For example, during the process, the compositemay undergo heat treatment or otherwise be dehydrated. Part or all ofthe solvent included in the solution may be removed as well during theprocess. For example, the composite may be subjected to a heat treatmentat a temperature ranging generally between 80 Celsius and 260 Celsius.Heat treatment of the composite (e.g., dehydration and/or solventremoval) may remove water and/or the solvent used at block 210. Thedehydration and/or solvent removal may occur over a time intervalgenerally between 3 to 24 hours. Other methods may be employed to removethe water and/or solvent including the use of a centrifugal separatorand others.

The produced composite (from either a metal alkoxide or a metalsilicate) produced at block 230 may be used to manufacture a lead-acidbattery. In one embodiment, the composite may form a portion of apositive or a negative plate for a lead-acid battery. Specifically, thecomposite may be included in an active material (e.g., a material thatproduces and stores electrical energy within a lead-acid battery) forthe lead-acid battery such as for the positive or the negative plate ofthe lead-acid battery.

In one embodiment, a lead-acid battery may include a first plate and asecond plate. The first plate may be a positive plate and the secondplate may be a negative plate, or vice versa. Each plate may include anactive material and a grid configured to provide support to the activematerial. The active material may include the composite for reactionswith the electrolyte to facilitate the charging and the discharging ofthe lead acid battery.

The composite produced based on the in-situ sol-gel reaction in thepresence of lead oxide may include lead oxide and the nanomaterial thathas been in-situ formed. In one non-limiting embodiment, the compositemay include a lead oxide particle and one or more nano-oxide particleson or around a surface of the lead oxide particle. The nano-oxideparticles may be dispersed or distributed among the lead oxide particlesto prevent the nano-oxide particles from aggregating with one another.For example, the nano-oxide particles dispersed or distributed among thelead oxide particles may include nano-sized oxide (e.g., silicondioxide) particles on or around surfaces of the lead oxide particles.The composite having the nanomaterial dispersed or distributed amonglead oxide particles may form an active material for the lead-acidbattery.

A grain size distribution (e.g., particle size distribution) of thecomposite may be illustrated by a curve (e.g., a histogram) in which thex-axis is the grain size of the composite and the y-axis is ameasurement of a quantity of the composite particles. The grain sizedistribution of the lead oxide may also be illustrated by such a curvein which the x-axis is the grain size of the lead oxide whereas they-axis is the measurement of a quantity of the lead oxide particles. Inone particular embodiment, the grain size distribution curve of thecomposite may include the grain size distribution curve of the leadoxide. That is, the grain size distribution curve of the composite maybe wider than the grain size distribution curve of the lead oxide. Insome embodiments, the grain size of the composite may be in a rangebetween 1 nanometer and 50 micrometers whereas the grain size of thelead oxide may be in a range between 1 micrometer and 50 micrometers.

A lead-acid battery or an active material for a lead-acid battery may bemanufactured using the composite that includes a lead oxide particle andone or more nano-oxide particles on or around the surface of the leadoxide particle. A surface area the composite may be greater than asurface area of the lead oxide. In one non-limiting embodiment, thesurface area of the composite may be at least 30% greater than thesurface area of the lead oxide. In other embodiments, however, thesurface area of the composite may be between a range of 10% and 300%greater than the surface area of the lead oxide.

FIG. 3 illustrates method 300 for an in-situ sol-gel reaction. Method300 starts at block 310. a solution for an in-situ sol-gel reaction maybe prepared. In one non-limiting example, 160 grams of isobutanol (e.g.,(CH₃)₂CHCH₂OH)), 25 grams of water, and 5 grams of acetylacetone (e.g.,C₅H₈O₂) may be combined. A quantity, for example, 0.15 grams ofpolyethylene glycol (may also be referred to as polyethylene oxide orpolyoxyethylene) may also be combined with the isobutanol, water andacetylacetone. In certain embodiments, the polyethylene glycol may bedissolved in the combined isobutanol, water and acetylacetone based onheating and/or mixing. Another quantity, for example, 20 grams oftetrabutyl titanate (e.g., Ti(OC₄H₉)₄) may also be added to the combinedisobutanol, water, acetylacetone and polyethylene glycol. In someembodiments, the tetrabutyl titanate may be added through mixing. Inthis particular embodiment, the solution prepared includes isobutanol,water, acetylacetone, polyethylene glycol, and tetrabutyl titanate.Operation proceeds to block 320.

At block 320, a catalyst such as nitric acid may be combined with thesolution prepared at block 310. A pH value of the solution may beadjusted by adjusting the amount of the nitric acid. In a non-limitingembodiment, the pH value of the solution may be adjusted to be withinthe range between 2 and 7, for example, the pH value may be adjusted to2.5. Operation proceeds to block 330.

At block 330, lead oxide may be combined with the solution having theadjusted pH value. In a non-limiting embodiment, 1000 grams of leadoxide may be combined with the solution. For example, the lead oxide maybe thoroughly mixed with the solution. The mixture of lead oxide andsolution may be heated to a temperature that is between a range of 40Celsius and 80 Celsius at which point an in-situ sol-gel reaction of thesolution may take place. In the non-limiting embodiment, after 1000grams of lead oxide is combined with the solution, the mixture may beheated to and maintained at 70 Celsius. Operation proceeds to block 340.

At block 340, a gel may be formed as part of the in-situ sol-gelreaction which may be maintained at a temperature of 70 Celsius for 65hours for an interval of time. The interval of time may be in a rangebetween 0.1 hours to 200 hours. Operation proceeds to block 350.

At block 350, a composite that includes the lead oxide and ananomaterial may be produced. Specifically, the in-situ sol-gel reactionmay produce titanium dioxide (e.g., TiO₂) in this non-limitingembodiment. The titanium dioxide that has been in-situ formed and thelead oxide may be pressed or ground after being cooled to roomtemperature, for example, between 15 Celsius and 25 Celsius. Subsequentto the pressing or grinding, the titanium oxide that has been in-situformed and the lead oxide may be treated to remove water and/or othersubstances such as the solvent. In a non-limiting embodiment, the waterand/or solvent removal process may include applying a temperature for 3hours to 24 hours to remove the water. The temperature for the waterand/or solvent removal process may be maintained at a particulartemperature within 100 Celsius to 260 Celsius. For example, the titaniumdioxide that has been in-situ formed and the lead oxide may be heated toand maintained at a temperature of 230 Celsius for 22 hours to produce acomposite that includes the lead oxide and nano-sized titanium oxide.Operation ends at block 350.

In a particular embodiment, 190 grams of ethanol (e.g., C₂H₆O) and 20grams of water may be combined. In addition, 0.5 grams of a polymer suchas phenol formaldehyde resin may be dissolved in the combined ethanoland water upon heating and/or mixing. After the phenol formaldehyderesin is combined, 30 grams of tetraethyl orthosilicate (e.g.,Si(OC₂H₅)₄) may be added to form a first solution. The first solution inthis example includes ethanol, water, phenol formaldehyde resin andtetraethyl orthosilicate.

Combining with the first solution with diluted sulfuric acid. Uponadjusting a pH value of the first solution to 2.5, a second solution isformed.

Combining the second solution with 1000 grams of lead oxide tofacilitate an oxidation reaction. The second solution may be thoroughlymixed with the lead oxide. The combined second solution and lead oxidemay be heated to and maintained at 75 Celsius for an in-situ sol-gelreaction to take place. When a gel is formed as part of the in-situsol-gel reaction, the temperature may be maintained at 75 Celsius for 50hours. The in-situ sol-gel reaction may produce silicon dioxide (e.g.,SiO₂) that is in-situ formed in the presence of the lead oxide.

After cooling the gel to room temperature, the gel may be pressed orground. Thereafter, the ground gel may be subject to a heat treatment ata temperature of 230 Celsius for 18 hours to produce a composite thatincludes the lead oxide and nano-sized silicon dioxide. The compositemay be used to manufacture an active material for a lead-acid battery.

In an alternative embodiment, 150 grams of isopropanol (e.g., isopropylalcohol or C₃H₈O) may be combined with 15 grams of water and 3 grams ofacetylacetone (e.g., C₅H₈O₂). Upon mixing and/or heating, 0.15 grams ofpolyethylene glycol may be dissolved in the mixture of isopropanol,water and acetylacetone. Thereafter, 15 grams of tetraethylorthosilicate (e.g., Si(OC₂H₅)₄) and 10 grams of tetrabutyl titanate(e.g., Ti(OC₄H₉)₄) may be added to form an initial solution. The initialsolution in this example, includes isopropanol, water, acetylacetone,polyethylene glycol, tetraethyl orthosilicate and tetrabutyl titanate.

Adding hydrochloric acid to the initial solution and adjusting a pHvalue of the initial solution to 3.6 to form a final solution.

Combining the final solution with 1000 grams of lead dioxide tofacilitate an oxidation reaction. The final solution may be thoroughlymixed with the lead dioxide. The combined final solution and leaddioxide may be heated to and maintained at 65 Celsius for an in-situsol-gel reaction to take place. When a gel is formed as part of thein-situ sol-gel reaction, the temperature may be maintained at 65Celsius for 65 hours. The in-situ sol-gel reaction may produce silicondioxide (e.g., SiO₂) and titanium dioxide (e.g., TiO₂) both of which arein-situ formed in the presence of the lead dioxide.

After cooling the gel to room temperature, the gel may be pressed orground. Thereafter, the ground gel may be subject to a heat treatment ata temperature of 230 Celsius for 20 hours to produce a composite thatincludes the lead dioxide, nano-sized silicon dioxide and nano-sizedtitanium dioxide. The composite may be used to manufacture an activematerial for a lead-acid battery.

FIG. 4 illustrates method 400 for making a component of a lead-acidbattery. Method 400 starts at block 410.

At block 410, a solution is prepared using metal alkoxide or silicate.In one particular embodiment, the solution may be a colloidal solution.Lead oxide is added to the solution. Operation proceeds to block 420.

At block 420, a composite that includes the lead oxide and ananomaterial may be formed. The nanomaterial may be in-situ formed basedon a sol-gel reaction of the solution. The in-situ sol-gel reaction mayfacilitate preventing the nanomaterial from aggregating with one anotherto form a material that is larger than the nanomaterial (e.g., amaterial that is no longer a nanomaterial). The composite may include alead oxide portion (e.g., a lead oxide particle) and a nanomaterialportion (e.g., one or more nanomaterial particle). In one particularembodiment, the composite may include a particle having an inner portionof lead oxide and an outer portion of nanomaterial. The method proceedsto block 430.

At block 430, an active material for a lead-acid battery may bemanufactured using the composite that includes the lead oxide and thenanomaterial. Operation ends at block 430.

The composite formed at block 420 may help to increase the stability andlife expectancy of the active material for the lead-acid battery. Forexample, when used in a lead-acid battery, the composite may help reducethe expansion or reduction of the active material during charging ordischarging of the lead-acid battery. The composite may also helpincrease the efficiency of the operation of the lead-acid battery. Forexample, the efficiency may increase as the grain size of the PbSO₄decreases (e.g., when the active material reacts with sulfuric acid,although other electrolytes are expressly included here) when thecomposite reacts with sulfuric acid. In some embodiments, a positiveplate or a negative plate of the lead-acid battery may include thecomposite. The positive or negative plate may be operable to react withan electrolyte (e.g., sulfuric acid in aqueous form) to charge ordischarge the lead-acid battery. The nanomaterial included in thecomposite may be an inert in the reactions for the discharging andcharging cycles.

Turning now to FIG. 5 in which method 500 for making a component of alead-acid battery is illustrated. Specifically, method 500 is directedto making a portion of a lead-acid battery such as lead-acid battery100. Method 500 starts at block 510.

At block 510, a first solution is produced by using an ion exchangeresin to process an aqueous solution of a silicate. The silicate mayinclude at least one of: may include at least one of: sodium silicate(e.g., Na₂SiO₃, Na₄SiO₄, or a combination of Na₂SiO₃ and Na₄SiO₄),potassium silicate (e.g., K₂SiO₃, K₄SiO₄, or a combination of K₂SiO₃ andK₄SiO₄), or lithium silicate (e.g., Li₂SiO₃, Li₄SiO₄, or a combinationof Li₂SiO₃ and Li₄SiO₄). In certain embodiments, the silicate may be inaqueous form, that is, the aqueous form of the silicate may include atleast one of: sodium silicate in aqueous form (may also be referred toas “sodium water glass”), potassium silicate in aqueous form (may alsobe referred to as “potassium water glass”), or lithium silicate inaqueous form (may also be referred to as “lithium water glass”). Otherforms of silicate may be specifically contemplated and included here.

In a particular embodiment, 210 grams of the aqueous solution isprocessed. In the 210 grams of the aqueous solution, the weightpercentage of sodium silicate is 8%. By processing the aqueous solutionof sodium silicate (e.g., sodium water glass) by using the ion exchangeresin (e.g., cation exchange resin), the sodium silicate to silicic acidwhich is included in the first solution. In one non-limiting example,the processing using the ion exchange resin may be facilitated by afixed bed ion exchanged process. Operation proceeds to block 520.

At block 520, a second solution is produced by combining the firstsolution produced at block 510 with a polymer and a catalyst. In onenon-limiting embodiment, the catalyst may include an acidic catalyst.The acidic catalyst may include at least one of: nitric acid, sulfuricacid, hydrochloric acid, phosphoric acid, propionic acid, acetic acid,formic acid, tartaric acid, citric acid, salicylic acid, oxalic acid, orany combination thereof. In an alternative embodiment, however, analkaline catalyst may be applied to the in-situ sol-gel reaction. Thealkaline catalyst may include at least one of: ammonia, ethanol amine,diethanolamine, triethanolamine, sodium hydroxide, potassium hydroxide,lithium hydroxide, magnesium hydroxide, or any combination thereof.Other catalysts are specifically contemplated and included here.

The polymer may include a naturally occurring polymer or a syntheticpolymer. The polymer may include but is not limited to a water-solublepolymer. For example, the polymer includes at least one of: polyethyleneglycol, polyvinyl alcohol, polyacrylamide, phenol formaldehyde resin, agelatin type material, polyethyleneimine, polyacrylic acid,polymethacrylic acid, or cellulose. In some embodiments, the polymer mayfacilitate stabilizing the second solution.

In the particular embodiment in which 210 grams of the aqueous solutionis processed to produce the first solution, a pH value of the firstsolution may be adjusted to a pH value of 4.16 by using sodium hydroxide(e.g., a diluted solution of sodium hydroxide). After adjusting the pHvalue, 2 grams of polyethylene glycol (e.g., a polyethylene glycolsolution) may be added to (e.g., mixed thoroughly with) the firstsolution whose pH value has been adjusted to produce the secondsolution. Operation proceeds to block 530.

At block 530, the second solution produced at block 520 is combined withlead oxide. In one non-limiting embodiment, the lead oxide beingcombined with the second solution may be in powder form. For example,lead oxide having a grain size that is between 1 micrometer and 50micrometers may be considered to be in powder form. However, the leadoxide is not limited to a particular grain size or a particular grainsize range. The lead oxide may include at least one of: lead monoxide(e.g., PbO), lead dioxide (e.g., PbO₂), triplumbic tetroxide (e.g.,Pb₃O₄), or any combination thereof.

In the particular embodiment in which the second solution is producedbased on 210 grams of the aqueous solution and 2 grams of polyethyleneglycol, 1000 grams of lead oxide may be combined with the secondsolution. The second solution may be thoroughly mixed with the leadoxide. Operation proceeds to block 540.

At block 540, a composite that includes the lead oxide and ananomaterial may be produced based on an in-situ sol-gel reaction of thesecond solution. The in-situ sol-gel reaction of the second solution maytake place in the presence of the lead oxide.

In the particular embodiment in which 1000 grams of the lead oxide iscombined with the second solution produced based on 210 grams of theaqueous solution and 2 grams of polyethylene glycol, the combined secondsolution and lead oxide may be heated to and maintained at 60 Celsiusfor an in-situ sol-gel reaction to take place. When a gel is formed aspart of the in-situ sol-gel reaction, the temperature may be maintainedat 60 Celsius for 26 hours. The in-situ sol-gel reaction may producesilicon dioxide (e.g., SiO₂) that is in-situ formed in the presence ofthe lead oxide. After cooling the gel to room temperature, the gel maybe pressed or ground. Thereafter, the ground gel may be subject to aheat treatment at a temperature of 230 Celsius for 18 hours to produce acomposite that includes the lead oxide and nano-sized silicon dioxide.Operation proceeds to block 550.

At block 550, the composite produced at block 540 may be incorporatedinto an active material for a lead-acid battery. The active materialhaving incorporated the composite may result in various favorableproperties of the lead-acid battery. For example, a life expectancy of alead-acid battery (e.g., a deep cycle battery) having the activematerial that includes the composite produced at block 540 may begreatly increased. Other properties of the lead-acid battery such as thespecific energy and power-to-weight ratio may also be increased.Operation ends at block 550.

Although specific embodiments have been described above, theseembodiments are not intended to limit the scope of the presentdisclosure, even where only a single embodiment is described withrespect to a particular feature. Examples of features provided in thedisclosure are intended to be illustrative rather than restrictiveunless stated otherwise. The above description is intended to cover suchalternatives, modifications, and equivalents as would be apparent to aperson skilled in the art having the benefit of this disclosure.

The scope of the present disclosure includes any feature or combinationof features disclosed herein (either explicitly or implicitly), or anygeneralization thereof, whether or not it mitigates any or all of theproblems addressed herein. Accordingly, new claims may be formulatedduring prosecution of this application (or an application claimingpriority thereto) to any such combination of features. In particular,with reference to the appended claims, features from dependent claimsmay be combined with those of the independent claims and features fromrespective independent claims may be combined in any appropriate mannerand not merely in the specific combinations enumerated in the appendedclaims.

What is claimed is:
 1. A method comprising: preparing a first mixturecomprising water, a polymer, and a metal silicate; combining lead oxidewith the first mixture to form a second mixture; and initiating anin-situ sol-gel reaction of the second mixture to produce a compositethat includes the lead oxide and a nanomaterial formed from the metalsilicate.
 2. The method of claim 1, wherein the polymer is a hydrophilicpolymer.
 3. The method of claim 1, wherein initiating the in-situsol-gel reaction comprises heating the second mixture.
 4. The method ofclaim 1, further comprising: removing, from the composite, at least aportion of the water.
 5. The method of claim 1, wherein the lead oxideis in powder form, and wherein the lead oxide in powder form has a grainsize of between 1 micrometer and 50 micrometers.
 6. The method of claim1, wherein the nanomaterial has a grain size that is between 1 nanometerand 100 nanometers.
 7. The method of claim 1, wherein the nanomaterialis an oxide of the metal silicate.
 8. The method of claim 1, wherein themetal silicate is a sodium silicate.
 9. The method of claim 1, whereinthe metal silicate is a lithium silicate.
 10. The method of claim 1,wherein the metal silicate is a potassium silicate.
 11. The method ofclaim 1, further comprising: adding a catalyst to the first mixture,wherein the catalyst comprises an acidic catalyst or an alkalinecatalyst.
 12. The method of claim 1, wherein the first mixturecomprises: 1 part of the metal silicate, 5 to 20 parts of water and0.0001 to 0.02 parts of the polymer.
 13. The method of claim 1, whereinthe lead oxide comprises at least one of: lead monoxide, lead dioxide,or triplumbic tetroxide.
 14. The method of claim 1, wherein the firstmixture is formed by: using an ion exchange resin to process an aqueoussolution of the metal silicate, wherein the metal silicate comprises atleast one of: sodium silicate, potassium silicate, or lithium silicate;and adding polymer to the aqueous solution.
 15. The method of claim 1,further comprising producing a lead-acid battery using the composite.16. A lead-acid battery that includes a composite produced by the methodof claim 1, the composite comprising a lead oxide and a nanomaterial,wherein the nanomaterial comprises non-aggregated nanomaterial.
 17. Thelead-acid battery of claim 16, wherein a positive electrode and/or anegative electrode of the lead-acid battery comprises the composite. 18.The lead-acid battery of claim 16, wherein the nanomaterial in thecomposite has a grain size that is between 1 nanometer and 100nanometers.
 19. The lead-acid battery of claim 16, wherein the leadoxide in the composite comprises at least one of: lead monoxide, leaddioxide, or triplumbic tetroxide.